Abstract: A bioluminescent assay for ATP in water borne bacteria is made by adding nitric acid to a water sample with concentrated bacteria to rupture the bacterial cells. The sample is diluted with sterile, deionized water, then mixed with a luciferase-luciferin mixture and the resulting light output of the bioluminescent reaction is measured and correlated with bacteria present. A standard and a blank also are processed so that the light output can be correlated to bacteria in the sample and system "noise" can be substracted from the readings.A chemiluminescent assay for iron porphyrins in water borne bacteria is made by adding luminol reagent to a water sample with concentrated bacteria and measuring the resulting light output of the chemiluminescent reaction. The light output is correlated with bacteria present. A standard and a blank are also processed so that the light output can be correlated to bacteria in the sample and system "noise" can be subtracted from the readings.

Abstract: An apparatus for processing multidimensional data with strong spatial characteristics, such as raw image data, characterized by a large number of parallel data streams in an ordered array, comprises a large number (e.g. 16,384 in a 128.times.128 array) of parallel processing elements operating simultaneously and independently on single bit slices of a corresponding array of incoming data streams under control of a single set of instructions. Each of the processing elements comprises a bidirectional data bus in communication with a register for storing single bit slices together with a random access memory unit and associated circuitry, including a binary counter/shift register device, for performing logical and arithmetical computations on the bit slices, and an I/O unit for interfacing the bidirectional data bus with the data stream source.

Abstract: A synthetic aperture radar correlation system including a moving diffuser located at the image plane of a radar processor. The output of the moving diffuser is supplied to a lens whose impulse response is at least as wide as that of the overall processing system. A significant reduction in clutter results.

Abstract: An apparatus is described which provides a numerical indication of the cloudiness at a particular time of a day. The apparatus includes a frame (18) holding several light sensors such as photovoltaic cells, with a direct sensor (12) mounted to directly face the sun and indirect sensors (13-16) mounted to face different portions of the sky not containing the sun. A light shield (30) shields the direct sensor from most of the sky except a small portion containing the sun, and also shields each of the indirect sensors from direct sunlight. The relative values of the outputs from the direct and indirect sensors, enables the generation of a numerical indication (56) of the degree of cloudiness at a particular time of day.

Abstract: A single-frequency multibeam synthetic aperture radar for large swath imaging is disclosed. Each beam illuminates a separate "footprint" (i.e., range and azimuth interval). The distinct azimuth intervals for the separate beams produce a distinct Doppler frequency spectrum for each beam. After range correlation of raw data, an optical processor develops image data for the different beams by spatially separating the beams to place each beam of different Doppler frequency spectrum in a different location in the frequency plane as well as the imaging plane of the optical processor. Selection of a beam for imaging may be made in the frequency plane by adjusting the position of an aperture, or in the image plane by adjusting the position of a slit. The raw data may also be processed in digital form in an analogous manner.

Abstract: A method and apparatus are provided for indicating the altitude of the tropopause or of an inversion layer wherein clear air turbulence (CAT) may occur, and the likely severity of any such CAT, which includes directing a passive microwave radiometer on the aircraft at different angles with respect to the horizon. The microwave radiation measured at a frequency of about 55 GHz represents the temperature of the air at an "average" range of about 3 kilometers, so that the sine of the angle of the radiometer times 3 kilometers equals the approximate altitude of the air whose temperature is measured. A plot of altitude (with respect to the aircraft) versus temperature of the air at that altitude, can indicate when an inversion layer is present and can indicate the altitude of the tropopause or of such an inversion layer. The plot can also indicate the severity of any CAT in an inversion layer.

Abstract: A method and apparatus for convection control of metallic halide vapor density in a metallic halide laser (10). More particularly, an apparatus is disclosed wherein a reservoir (48) containing copper chloride (62), which in the exemplary embodiment is the metallic halide chosen, is heated so that the copper chloride is maintained in a liquid form. The apparatus includes a means for flowing a buffer gas, which in the exemplary embodiment is neon, over the liquid copper chloride to provide a mixture of copper chloride vapor and neon (72') above the liquid copper chloride. A conduit (50) for providing fluid communication between the reservoir (68) containing the copper chloride vapor/neon mixture and the laser (10) is also included. The copper chloride vapor density in the laser is related to the liquid copper chloride temperature and the neon flow rate through the reservoir (68).

Abstract: A new and improved secure communication system is provided. A product code, formed from two pseudorandom sequences of digital bits, is used to encipher or scramble data prior to transmission. The two pseudorandom sequences are periodically changed at intervals before they have had time to repeat. One of the two sequences is transmitted continuously with the scrambled data for synchronization.In the receiver portion of the system, the incoming signal is compared with one of two locally generated pseudorandom sequences until correspondence between the sequences is obtained. At this time, the two locally generated sequences are formed into a product code which deciphers the data from the incoming signal. Provision is made to ensure synchronization of the transmitting and receiving portions of the system.

Abstract: A mechanical end joint system, useful for the transverse connection of strut elements to a common node, comprises a node joint half 15 with semicircular tongue 14 and groove 60 and a strut joint half 24 with semicircular tongue 25 and groove 21. The two joint halves are engaged transversely and the connection is made secure by the inherent physical property characteristics of locking latches 12 and 26 (FIGS. 1-6) or by a spring-actioned shaft 70 (FIG. 7). A quick release mechanism (FIG. 7) provides rapid disengagement of the joint halves.

Abstract: NiCrAl alloys are improved by the addition of zirconium. These alloys are in the .beta. or .gamma./.gamma.'+.beta. region of the ternary system.Zirconium is added in a very low amount between 0.06 and 0.20 weight percent. There is a narrow optimum zirconium level at the low value of 0.13 weight percent.Maximum resistance to cyclic oxidation is achieved when the zirconium addition is at the optimum value.

Abstract: An optical temperature gauge using a semiconductor crystal (12) having a band-edge shift property which is temperature dependent. An external narrow band light source (10) provides optical excitation through an optical fiber (11) and light energy thus passed through the crystal (12) is conveyed by a second optical fiber (13) to a light-to-electric transducer (14) at an external location, the crystal (12) thereby being locatable in cryogenic or other systems, to provide remote read-out. The light wavelength is varied (scanned) in a repetitive pattern in source (10), the instantaneous wavelength passing over the band-edge wavelength during each cycle of the scan. The timing of the crossover is related to the temperature of the crystal by electronic means (15 and 17). Several alternative elements of instrumentation are disclosed.

Abstract: A method and device for detecting the presence of a substance having predetermined characteristics. More particularly, a device is disclosed wherein a discharge grid (20) is provided having a sufficiently high voltage potential across its grid electrodes (32 and 36) so that the substance having the predetermined characteristics will cause an electric spark discharge to occur between electrodes, the electric spark discharge altering the predetermined characteristics of the substance by oxidation and/or vaporization so that the substance is no longer detectable by an electric spark discharge. A means for counting the number of electric spark discharges is provided (96), a count providing an indication of the concentration of the substance having the predetermined characteristics. One embodiment disclosed detects longitudinally extending carbon fibers suspended in a gaseous medium (12). Another embodiment provides for the detection of carbon fibers (66) adhesively attached to a collection tape (68).

Abstract: An electronically controllable apparatus is described which modulates a continuous wave laser beam 22 so as to produce an output beam 42 consisting of coherent "pulses" that are electronically controllable as to both pulse repetition rate and pulse width. The apparatus includes two acoustic devices 24, 26 positioned so that the laser beam passes through them in sequence, and apparatus 32 or 34 for passing sound waves through the devices to frequency shift the laser radiation as well as to diffract it. Each acoustic device such as 24 generates sound waves containing a group of frequencies which result in spaced pulses. The spreading of a laser beam at 40 which emanates from the first acoustic device 24 is countered by the second acoustic device 26 to produce a collimated, coherently pulsed, laser beam 42.

Abstract: Apparatus for converting a radiant energy image into corresponding electrical signals including an image converter. The image converter includes a substrate 20 of semiconductor material, an insulating layer 23 on the front surface of the substrate and an electrical contact 22 on the back surface of the substrate. A first series of parallel transparent conductive stripes 25 is on the insulating layer with a processing circuit 33 connected to each of the conductive stripes for detecting the modulated voltages generated thereon. In a first embodiment of the invention (FIG. 5), a modulated light stripe 38 perpendicular to the conductive stripes 25 scans the image converter. The resulting modulated signals generated on the conductive stripes are detected by the processing circuits 40 to produce signals that represent the image focused on the image converter. In a second embodiment of the invention (FIG.

Abstract: A method of repairing cracks or damaged areas in glass, in particular, glass coatings provided on tile. The method includes removing the damaged area using a high speed diamond burr drilling out a cavity that extends slightly into the base material of the tile. All loose material is then cleaned from the drilled out cavity and the cavity is filled adjacent the upper surface of the coating with a filler material including chopped silica fibers mixed with a binder. The filler material is packed into the cavity and a repair coating is applied by means of a brush or sprayed thereover. The repair includes borosilicate suspended in solution. Heat is applied at approximately 2100.degree. F. for approximately five (5) minutes for curing the coating, causing boron silicide particles of the coating to oxidize forming a very fluid boron-oxide rich glass which reacts with the other frits to form an impervious, highly refractory layer.

Abstract: A high power metallic halide laser capable of providing 300 watts of output power. More specifically, a laser amplification system is disclosed whereby a metallic halide vapor such as copper chloride (Cu.sub.3 Cl.sub.3) is caused to flow through a laser amplifier (10) and a heat exchanger means (24) in a closed loop system whereby the flow rate is altered to control the temperature rise across the length of the laser amplifier. In the copper chloride laser described in an exemplary embodiment, the copper atoms within the laser amplifier should not exceed a temperature of 3000.degree. K. so that the number of copper atoms in the metastable state will not be high enough to prevent amplification in the amplifier. In addition, a molecular dissociation apparatus (20) is provided at the input to the laser amplifier for dissociating the copper chloride into copper atoms and ions and chlorine atoms and ions.

Abstract: Input signals from sensor (S) in a redundancy management system are provided redundantly in parallel so that a primary control signal may be selected. Median value signals for groups of three sensors are detected in median value selectors (30, 32, 34, 36, 40) of selection filters (F). The detected median value signals are then also compared in a subtractor/comparator (38) to determine whether any of them exceed the others by an amount greater than the signal level for a failed sensor. If so, the exceeding detected medium value signal is sent to a control computer (10) as the primary control signal. If not, the lowest level detected medium value signal is sent as the primary control signal.

Abstract: A Schottky barrier solar cell consists of a thin substrate of low cost material with at least the top surface of the substrate being electrically conductive. A thin layer of heavily doped n-type polycrystalline germanium, with crystalline sizes in the submicron range, is deposited on the substrate. But first a passivation layer may be deposited on the substrate to prevent migration of impurities into the polycrystalline germanium on a substrate of low-cost conductive material. Then the polycrystalline germanium is recrystallized to increase the crystal sizes in the germanium layer to not less than 5 microns, and preferably considerably more. It serves as a base layer on which a thin layer of gallium arsenide is vapor-epitaxially grown to a selected thickness. Then, a thermally-grown oxide layer of a thickness of several tens of angstroms is formed on the gallium arsenide layer.

Abstract: Production of strong lightweight membrane structure by applying a thin reflective coating such as aluminum to a rotating cylinder, applying a mesh material such as nylon over the aluminum coating, coating the mesh overlying the aluminum with a polymerizing material such as a para-xylylene monomer gas to polymerize as a film bound to the mesh and the aluminum, and applying an emissivity increasing material such as chromium and silicon monoxide to the polymer film to disperse such material colloidally into the growing polymer film, or applying such material to the final polymer film, and removing the resulting membrane structure from the cylinder.

Abstract: An echo tracker/range finder or altimeter in which the pulse repetition frequency (PFR) of a predetermined plurality of transmitted pulses is adjusted so that echo pulses received from a reflecting object are positioned between transmitted pulses and divide their interpulse time interval into two time intervals having a predetermined ratio with respect to each other. The thus-adjusted PRF is related to the range of the reflecting object. More specifically, the invention provides a means whereby the arrival time of a plurality of echo pulses is defined as the time at which a composite echo pulse formed of a sum of the individual echo pulses has the highest amplitude. This arrival time is determined by dividing an interpulse time interval between adjacent transmitted pulses into a predetermined plurality of corresponding time increments.